Communication system and method, information processing terminal and method, and information processing device and method

ABSTRACT

The present invention relates to a communication system and method, an information processing terminal and method, and an information processing device and method which enable simple and secure restricted access. When a PDA  11  is brought close, a reader  2  of a personal computer  1  reads a device ID form an IC tag  12 . The personal computer  1  registers device IDs on a connection permission list, and permits only devices registered on the list to connect. When being instructed to perform accessing, the PDA  11  controls a communication unit to access the personal computer  1  and to transmits its device ID. The personal computer  1  determines whether or not the transmitted ID is registered on the connection permission list, and permits the connection when determining that the ID is registered. The present invention can be applied to various information processing devices such as a personal computer and a PDA.

This is a continuation of application Ser. No. 12/801,153, filed May 25,2010 now U.S. Pat. No. 8,019,359, currently allowed, which is acontinuation of application Ser. No. 11/905,912, filed Oct. 5, 2007, nowU.S. Pat. No. 7,751,800, which is a divisional of U.S. application Ser.No. 10/465,958, filed Jun. 27, 2003, now U.S. Pat. No. 7,406,323, whichis a U.S. national stage filing under 35 U.S.C. §371 of PCT/JP02/11169,filed Oct. 28, 2002, and claims priority of Japanese Patent ApplicationNo. 2001-336619, filed Nov. 1, 2001, all of which are incorporatedherein by reference in their entirety.

TECHNICAL FIELD

The present invention relates to communication systems and methods,information processing terminals and methods, and information processingdevices and methods, and in particular, to a communication system andmethod, an information processing terminal and method, and aninformation processing device and method that enable simple and securerestricted access.

BACKGROUND ART

With the recent developments in communication technology, users havecome to obtain required information by using various communicationdevices to access a predetermined server, regardless of the location ofthe users and the time of day. Users can confirm required informationanytime by using, for example, cellular phones, PDAs (Personal DigitalAssistants), etc.

For the administrator of the server, it may be required to restrict freeaccess to the server. In this case, for example, it is common that theIP addresses of devices which are allowed to access the server areregistered beforehand, and users accessing the server are requested toinput passwords.

By way of example, when predetermined information is delivered only topersons gathering for an event, access is restricted by registeringbeforehand the addresses of devices used by those persons.

However, in order to restrict access, in the case of registeringbeforehand the IP addresses of all the devices for which the serverallows access, a problem occurs in that the operation is verycomplicated.

Although such a problem does not occur when the number of the devicesallowed to access is relatively small, when the number is as large asseveral hundred or several thousand, the operation of registering the IPaddresses of all the devices becomes very difficult.

In addition, as described above, when access is restricted by requestingusers to input passwords notified to them beforehand, there is apossibility that some users may forget their passwords. Also, even ifthe users remember the passwords, they are inconvenienced by having toinput their passwords, which is a problem.

DISCLOSURE OF INVENTION

The present invention is made in view of the above circumstances, andenables simple and secure restricted access.

An information processing terminal for a first communication system ofthe present invention comprises a providing means for providing, bymeans of wireless communication, identification information of theinformation processing terminal to an information processing devicepositioned nearby; and a first communication means for performing wiredor wireless communication with the information processing device. Whenan instruction to connect to the information processing device is given,the first communication means transmits the identification informationto the information processing device; and performs communication whencommunication is permitted by the information processing device based onthe transmitted identification information. An information processingdevice comprises an acquiring means for acquiring the identificationinformation by wireless communication from the information processingterminal, which is positioned nearby, a second communication means forperforming wired or wireless communication with the informationprocessing terminal, and a storage means for storing the identificationinformation acquired by the acquiring means. When the secondcommunication means receives the identification information from theinformation processing terminal, and it is determined that the receivedidentification information is identical to the identificationinformation stored in the storage means, the second communication meansperforms communication with the information processing terminal.

A communication method for a first communication system of the presentinvention includes a providing step for providing identificationinformation of the information processing terminal by wirelesscommunication to an information processing device positioned nearby, anda first communication step for performing wired or wirelesscommunication with the information processing device. When aninstruction to connect to the information processing device is given,the identification information is transmitted to the informationprocessing device, and communication is performed when communication ispermitted by the information processing device based on the transmittedidentification information. The communication method includes anacquiring step for acquiring the identification information by wirelesscommunication from an information processing terminal positioned nearby,a second communication step for performing wired or wirelesscommunication with the information processing terminal, and a storagestep for storing the identification information acquired by theacquiring step. When the identification information is received from theinformation processing terminal, and it is determined that the receivedidentification information is identical to the identificationinformation stored by the storage step, the communication with theinformation processing terminal is performed.

A first information processing terminal of the present inventioncomprises a providing means for providing identification information ofthe information processing terminal by wireless communication to aninformation processing device positioned nearby, and a communicationmeans for performing wired or wireless communication with theinformation processing device. When an instruction to connect to theinformation processing device is given, the communication meanstransmits the identification information to the information processingdevice, and performs communication when communication is permitted bythe information processing device based on the transmittedidentification information.

The information processing terminal further comprises a storage meansfor storing communication information for performing communication withthe information processing device. Based on the communicationinformation stored in the storage means, the communication meansaccesses the information processing device and transmits theidentification information.

An information processing method for a first information processingterminal of the present invention includes a providing step forproviding identification information of the information processingterminal by wireless communication to an information processing devicepositioned nearby, and a communication step for performing wired orwireless communication with the information processing device. When aninstruction to connect to the information processing device is given,the identification information is transmitted to the informationprocessing device, and communication is performed when communication ispermitted by the information processing device based on the transmittedidentification information.

A program of the present invention includes a provision control step forcontrolling provision of identification information of one side bywireless communication to an information processing device positionednearby, and a communication control step for controlling wired orwireless communication with the information processing device, andcauses a computer to execute transmitting identification information tothe information processing device when an instruction to connect to theinformation processing device is given, and performing communicationwhen communication is permitted by the information processing devicebased on the transmitted identification information.

A first information processing device of the present invention comprisesan acquiring means for acquiring first identification information bywireless communication from an information processing terminalpositioned nearby, a communication means for performing wired orwireless communication with the information processing terminal, and astorage means for storing the first identification information acquiredby the acquiring means. When the communication means receives secondidentification information from the information processing terminal, andit is determined that the received second identification information isidentical to the first identification information stored in the storagemeans, the communication means performs communication with theinformation processing terminal.

The storage means can delete the first identification information when apredetermined period passes after the first identification informationis stored.

An information processing method for a first information processingdevice of the present invention includes an acquiring step for acquiringfirst identification information by wireless communication from aninformation processing terminal positioned nearby, a communication stepfor performing wired or wireless communication with the informationprocessing terminal, and a storage step for storing the firstidentification information acquired by the acquiring step. When secondidentification information is received from the information processingterminal, and it is determined that the received second identificationinformation is identical to the first identification information storedby the processing of the storage step, communication with theinformation processing terminal is performed.

A program of the present invention includes an acquisition control stepfor controlling acquisition by wireless communication of firstidentification information from an information processing terminalpositioned nearby, a communication control step for controlling wired orwireless communication with the information processing terminal, and astorage control step for controlling storage of the first identificationinformation acquired by the processing of the acquisition control step,and causes a computer to execute performing communication with theinformation processing terminal when second identification informationis received from the information processing terminal and it isdetermined that the received second identification information isidentical to the first identification information stored by theprocessing of the storage control step.

An information processing terminal for a second communication system ofthe present invention comprises an acquiring means for acquiring, fromthe information processing device positioned nearby, communicationinformation for performing communication with the information processingdevice by wireless communication, and a password, and a firstcommunication means for performing wired or wireless communication withthe information processing device. When an instruction to connect to theinformation processing device is given, the first communication meansaccesses the information processing device based on the communicationinformation acquired by the acquiring means, transmits the password tothe information processing device, and performs communication whencommunication is permitted by the information processing device-based onthe transmitted password. An information processing device comprises aproviding means for providing predetermined information by wirelesscommunication to an information processing terminal positioned nearby, asecond communication means for performing wired or wirelesscommunication to the information processing terminal, and a storagemeans for storing the communication information for performingcommunication by the second communication means, and the password. Theproviding means provides, as the information, the communicationinformation and password stored in the storage means to the informationprocessing terminal. The second communication means performscommunication with the information processing terminal when receivingthe password transmitted from the information processing terminal, andit is determined that the received password is identical to the passwordstored in the storage means.

A communication method for a second communication system of the presentinvention includes an acquiring step for acquiring, from an informationprocessing device positioned nearby, communication information forperforming communication with the information processing device bywireless communication, and a password, and a first communication stepfor performing wired or wireless communication with the informationprocessing device. When an instruction to connect to the informationprocessing device is given, the information processing device isaccessed based on the communication information acquired by theprocessing of the acquiring step, the password is transmitted to theinformation processing device, and communication is performed whencommunication is permitted by the information processing device based onthe transmitted password. The method includes a providing step forproviding predetermined information by wireless communication to aninformation processing terminal positioned nearby, a secondcommunication step for performing wired or wireless communication to theinformation processing terminal, and a storage step for storing thecommunication information for performing communication by the processingof the second communication step and the password. The communicationinformation and password stored by the processing of the storage stepare provided as the information to the information processing terminal.When the password transmitted from the information processing terminalis received, and it is determined that the received password isidentical to the password stored by the processing of the storage step,communication with the information processing terminal is performed.

A second information processing terminal of the present inventioncomprises an acquiring means for acquiring, from the informationprocessing device positioned nearby, communication information forperforming communication with the information processing device bywireless communication, and a password and a communication means forperforming wired or wireless communication with the informationprocessing device. When an instruction to connect to the informationprocessing device is given, the communication means accesses theinformation processing device based on the communication informationacquired by the acquiring means, transmits the password to theinformation processing device, and performs communication whencommunication is permitted by the information processing device based onthe transmitted password.

A second information processing method of the present invention for aninformation processing terminal includes an acquiring step foracquiring, from an information processing device positioned nearby,communication information for performing communication with aninformation processing device by wireless communication and a password,and a communication step for communicating with the informationprocessing device by wire or wireless. When an instruction to connect tothe information processing device is given, the information processingdevice is accessed based on the communication information acquired bythe processing of the acquiring step, the password is transmitted to theinformation processing device, and communication is performed whencommunication is permitted by the information processing device based onthe transmitted password.

A program of the present invention includes an acquisition control stepfor controlling acquisition, from an information processing devicepositioned nearby, of communication information for performingcommunication with an information processing device by wirelesscommunication, and a password, and a communication control step forcontrolling wired or wireless communication with the informationprocessing device. The program causes a computer to execute accessingthe information processing device based on the communication informationacquired by the processing of the acquisition control step when aninstruction to connect to the information processing device is given,transmitting the password to the information processing device, andperforming communication when communication is permitted by theinformation processing device based on the transmitted password.

A second information processing device of the present inventioncomprises a providing means for providing predetermined information bywireless communication to an information processing terminal positionednearby, a communication means for performing communication with aninformation processing terminal by wire or wireless, and a storage meansfor storing communication information for performing communication bythe communication means and a first password. The providing meansprovides, as the information, the communication information and firstpassword stored in the storage means to the information processingterminal, and the communication means performs communication with theinformation processing terminal when receiving a second passwordtransmitted from the information processing terminal, and it isdetermined that the received second password is identical to the firstpassword.

The storage means can change the first password in a predeterminedcycle.

An information processing method for a second information processingdevice of the present invention includes a providing step for providingpredetermined information by wireless communication to an informationprocessing terminal positioned nearby, a communication step forperforming wired or wireless communication with the informationprocessing terminal, and a storage step for storing communicationinformation for performing communication by the communication step and afirst password. The communication information and first password storedby the processing of the storage step are provided as the information tothe information processing terminal, and when a second passwordtransmitted from the information processing terminal is received and itis determined that the received second password is identical to thefirst password, communication with the information processing terminalis performed.

A program of the present invention includes a provision control step forcontrolling provision by wireless communication of predeterminedinformation to an information processing terminal positioned nearby; acommunication control step for controlling wired or wirelesscommunication with the information processing terminal, and a storagecontrol step for controlling storage of communication information forperforming communication by the processing of the communication controlstep and a first password. The program causes a computer to executeproviding, as the information, the communication information and firstpassword stored by the processing of the storage control step to theinformation processing terminal, and performing communication with theinformation processing terminal when a second password transmitted fromthe information processing terminal is received and it is determinedthat the received second password is identical to the first password.

An information processing terminal for a third communication system ofthe present invention comprises a first providing means for providingidentification information, of the information processing terminal bywireless communication to an information processing device positionednearby, a first acquiring means for acquiring, from the informationprocessing device, communication information for performingcommunication with the information processing device and a password, anda first communication means for performing wired or wirelesscommunication with the information processing device. When aninstruction to connect to the information processing device is given,the first communication means accesses the information processing devicebased on the communication information acquired by the first acquiringmeans, transmits the identification information and the password to theinformation processing device, and performs communication whencommunication is permitted by the information processing device based onthe transmitted identification information and password. An informationprocessing device comprises an second providing means for providingpredetermined information by wireless communication to an informationprocessing terminal positioned nearby, a second acquiring means foracquiring the identification information from the information processingterminal by wireless communication, a first storage means for storingthe identification information acquired by the second acquiring means, asecond communication means for performing wired or wirelesscommunication with the information processing terminal, and a secondstorage means for storing the communication information for performingcommunication by the second communication means and the password. Thesecond providing means provides, as the information, the communicationinformation and password stored in the second storage means to theinformation processing terminal. The second communication means performscommunication with the information processing terminal when receivingthe identification information and password transmitted from theinformation processing terminal, and it is determined that the receivedidentification information is identical to the identificationinformation stored in the first storage means and it is determined thatthe received password is identical to the password stored in the secondstorage means.

A communication method for a third communication system of the presentinvention included a first providing step for providing identificationinformation of an information processing terminal by wirelesscommunication to an information processing device positioned nearby, afirst acquiring step for acquiring, from the information processingdevice, communication information for performing communication with theinformation processing device and a password, and a first communicationstep for performing wired or wireless communication with the informationprocessing device. When an instruction to connect to the informationprocessing device is given, the information processing device isaccessed based on the communication information acquired by theprocessing of the first acquiring step, the identification informationand the password are transmitted to the information processing device,and communication is performed when communication is permitted based onthe transmitted identification information and password. An informationprocessing method for an information processing device includes a secondproviding step for providing predetermined information by wirelesscommunication to an information processing terminal positioned nearby, asecond acquiring step for acquiring the identification information fromthe information processing terminal by wireless communication, a firststorage step for storing the identification information acquired by theprocessing of the second acquiring step, a second communication step forperforming wired or wireless communication to the information processingterminal, and a second storage step for storing the communicationinformation for performing communication by the processing of the secondcommunication step and the password. The communication information andpassword stored by the processing of the second storage step areprovided as the information to the information processing terminal, andwhen the identification information and password transmitted from theinformation processing terminal are received, and it is determined thatthe received identification information is identical to theidentification information stored by the processing of the first storagestep and it is determined that the received password is identical to thepassword stored by the processing of the second storage step,communication with the information processing terminal is performed.

A third information processing terminal of the present inventioncomprises a providing means for providing identification information ofan information processing terminal by wireless communication to aninformation processing device positioned nearby, an acquiring means foracquiring, from the information processing device, the communicationinformation for performing communication with the information processingdevice by wireless communication, and a communication means forperforming wired or wireless communication with the informationprocessing device. When an instruction to connect to the informationprocessing device is given, the communication means accesses theinformation processing device based on the communication informationacquired by the acquiring means, transmits the identificationinformation and the password to the information processing device, andperforms communication when communication is permitted by theinformation processing device based on the transmitted identificationinformation and password.

An information processing method for a third information processingterminal for the present invention includes a providing step foridentification information of one side to an information processingdevice positioned nearby, an acquiring step for acquiring, from theinformation processing device, communication information for performingcommunication with an information processing device by wirelesscommunication, and a password, and a communication step for performingwired or wireless communication with information processing device. Whenan instruction to connect to the information processing device is given,the information processing device is accessed based on the communicationinformation acquired by the processing of the acquiring step, theidentification information and the password are transmitted to theinformation processing device, and communication is performed whencommunication is permitted by the information processing device based onthe transmitted identification information and password.

A program of the present invention comprises a provision control stepfor controlling provision by wireless communication of identificationinformation of one side to an information processing device positionednearby, an acquisition control step for controlling acquisition from aninformation processing device by wireless communication of communicationinformation for performing communication with the information processingdevice and a password, and a communication control step for controllingwired or wireless communication with the information processing device.The program causes a computer to execute accessing the informationprocessing device based on the communication information acquired by theprocessing of the acquisition control step when an instruction toconnect to the information processing device is given, transmitting theidentification information and the password to the informationprocessing device, and performing communication when communication ispermitted by the information processing device based on the transmittedidentification information and password.

A third information processing device of the present invention comprisesa providing means for providing predetermined information by wirelesscommunication to an information processing terminal positioned nearby,an acquiring means for acquiring, from an information processingterminal, first identification information by wireless communication, afirst storage means for storing the first identification informationacquired by the acquiring means, a communication means for performingwired or wireless communication with the information processingterminal, and a second storage means for storing communicationinformation for performing communication by the communication means anda first password. The providing means provides, as the information, thecommunication information and first password stored in the secondstorage means to the information processing terminal, and thecommunication means performs communication with the informationprocessing terminal when receiving the second identification informationand second password transmitted from the information processingterminal, and it is determined that the received second identificationinformation is identical to the first identification information storedin the first storage means and it is determined that the received secondpassword is identical to the first password.

The first storage means can delete the first identification informationwhen a predetermined period passes after the first identificationinformation is stored.

The second storage means can change the first password in apredetermined cycle.

An information processing method for a third information processingdevice of the present invention for an information processing deviceincludes a providing step for providing predetermined information bywireless communication to an information processing terminal positionednearby, an acquiring step for acquiring first identification informationfrom an information processing terminal by wireless communication, afirst storage step for storing the first identification informationacquired by the processing of the acquiring step, a communication stepfor performing wired or wireless communication with the informationprocessing terminal, and a second storage step for storing communicationinformation for performing communication by the processing of thecommunication step, and a first password. The communication informationand first password stored by the processing of the second storage stepare provided as the information to the information processing terminal.When the second identification information and second passwordtransmitted from the information processing terminal are received, andit is determined that the received second identification information isidentical to the first identification information stored by theprocessing of the first storage step and it is determined that thereceived second password is identical to the first password,communication with the information processing terminal is performed.

A program of the present invention includes a provision control step forcontrolling provision of predetermined information by wirelesscommunication with an information processing terminal positioned nearby,an acquisition control step for controlling acquisition by wirelesscommunication of first identification information from an informationprocessing terminal, a storage control step for controlling storage ofthe first identification information acquired by the processing of theacquisition control step, a communication control step for controllingwired or wireless communication with the information processingterminal, and a second storage control step for controlling storage ofcommunication information for performing communication by the processingof the communication control step and the first password. The programexecutes a computer to execute providing, as the information, thecommunication information and first password stored by the processing ofthe second storage control step, and performing communication with theinformation processing terminal when the second identificationinformation and second password transmitted from the informationprocessing terminal are received, and it is determined that the receivedsecond identification information is identical to the firstidentification information stored by the processing of the first storagecontrol step and it is determined that the received second password isidentical to the first password.

In a first communication system and method of the present invention,when an information processing terminal provides, by wirelesscommunication, identification information of the terminal to aninformation processing device positioned nearby, performs communicationby wire or wireless, and is instructed to connect to the informationprocessing device, the identification information is transmitted to theinformation processing device, and communication is performed whencommunication is permitted by the information processing device based onthe transmitted identification. Also, the identification information isacquired from the information processing terminal, which is positionednearby, communication with the information processing terminal isperformed by wire or wireless, and the acquired identificationinformation is stored. When the identification information is receivedfrom the information processing terminal, and it is determined that thereceived identification information is identical to the storedidentification information, communication with the informationprocessing terminal is performed.

In a first information processing terminal, method, and program of thepresent invention, identification information of the terminal isprovided by wireless communication to an information processing devicepositioned nearby, and communication with the information processingdevice is performed by wire or wireless. Also, when an instruction toconnect to the information processing device is given, theidentification information is transmitted to the information processingdevice, and communication is performed when communication is permittedby the information processing device based on the transmittedidentification information.

In a first information processing device, method, and program of thepresent invention, first identification information is acquired bywireless communication from an information processing terminalpositioned nearby, communication with the information processingterminal is performed by wire or wireless, and the acquired firstidentification information is stored. Also, when second identificationinformation is received from the information processing terminal, and itis determined that the received second identification information isidentical to the first identification information, communication withthe information processing terminal is performed.

In a second communication system and method of the present invention,from an information processing device positioned nearby, communicationinformation for performing communication with the information processingdevice by wireless communication and a password are acquired by aninformation processing terminal, and communication with the informationprocessing device is performed by wire or wireless. Also, when aninstruction to connect to the information processing device is given,the information processing device is accessed based on the acquiredcommunication information, the password is transmitted to theinformation processing device, and communication is performed when it ispermitted by the information processing device based on the transmittedpassword. In addition, the information processing device providespredetermined information by wireless communication to an informationprocessing terminal positioned nearby, and communication with theinformation processing terminal by wire or wireless and thecommunication information for performing communication and the passwordare stored. The stored communication information and password areprovided to the information processing terminal. When the passwordtransmitted from the information processing terminal is received, and itis determined that the received password is identical to the storedpassword, communication with the information processing terminal isperformed.

In a second information processing terminal, method, and program of thepresent invention, from an information processing device positionednearby, communication information for performing communication with theinformation processing device and a password are acquired by wirelesscommunication, and communication with the information processing deviceis performed by wire or wireless. Also, when an instruction to connectto the information processing device is given, the informationprocessing device is accessed based on the acquired communicationinformation, the password is transmitted to the information processingdevice, and communication is performed when it is permitted based on thetransmitted password.

In a second information processing device, method, and program of thepresent invention, predetermined information is provided by wirelesscommunication to an information processing terminal positioned nearby,communication with the information processing terminal is performed bywire or wireless, and communication information for performingcommunication and a first password are stored. The stored communicationinformation and first password are provided to the informationprocessing terminal. When a second password transmitted from theinformation processing terminal is received, and it is determined thatthe received second password is identical to the first password,communication with the information processing terminal is performed.

In a third information processing terminal, method, and program of thepresent invention, identification information of an informationprocessing terminal is provided by wireless communication from theinformation processing terminal to an information processing devicepositioned nearby, communication information for performingcommunication with the information processing device is acquired fromthe information processing device by wireless communication, andcommunication with the information processing device is performed bywire or wireless. When an instruction to connect to the informationprocessing device is given, the information processing device isaccessed based on the acquired communication information, thecommunication information and the password are transmitted to theinformation processing device; and communication is performed whencommunication is permitted based on the transmitted communicationinformation and password. In addition, predetermined information isprovided by wireless communication from an information processing deviceto the information processing terminal, which is positioned nearby. Fromthe information processing terminal, identification information isacquired by wireless communication, and the acquired identificationinformation is stored. Wired or wireless communication with theinformation processing terminal is performed, and communicationinformation for performing communication, and a password are stored.Also, the stored communication information and password are provided tothe information processing terminal. When communication information andpassword transmitted from the information processing terminal arereceived, and it is determined that the received identificationinformation is identical to the stored identification information and itis determined that the received password is identical to the storedpassword, communication with the information processing terminal isperformed.

In a third information processing terminal, method, and program of thepresent invention, identification information of the terminal isprovided by wireless communication to an information processing devicepositioned nearby, communication information for performingcommunication with the information processing device and a password areacquired from the information processing device, and communication withthe information processing device is performed by wire or wireless.Also, when an instruction to connect to the information processingdevice is given, the information processing device is accessed based onthe acquired identification information, the identification informationand the password are transmitted to the information processing device,and communication is performed when it is permitted by the informationprocessing device based on the transmitted identification informationand password.

In a third information processing device, method, and program of thepresent invention, predetermined information is provided by wirelesscommunication to an information processing terminal positioned nearby,first identification information is acquired from the informationprocessing terminal by wireless communication. The acquired firstidentification information is stored and communication with theinformation processing terminal is performed by wire or wireless, andcommunication information for performing communication and a firstpassword are stored. The stored communication information and firstpassword are provided to the information processing terminal. Whensecond identification information and a second password, transmittedfrom the information processing terminal, are received, and it isdetermined that the received second identification information isidentical to the stored first identification information and it isdetermined that the received second password is identical to the firstpassword, communication with the information processing terminal isperformed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of an example of a communication system towhich the present invention is applied.

FIG. 2 is a block diagram showing an example of the personal computer inFIG. 1.

FIG. 3 is a block diagram showing an example of the reader in FIG. 2.

FIG. 4 is a block diagram showing an example of the PDA in FIG. 1.

FIG. 5 is a block diagram showing an example of the IC tag in FIG. 4.

FIG. 6 is a flowchart illustrating a process of the personal computer inFIG. 2.

FIG. 7 is a flowchart illustrating a process of the PDA in FIG. 4.

FIG. 8 is a flowchart illustrating another process of the PDA in FIG. 4.

FIG. 9 is a flowchart illustrating another process of the personalcomputer in FIG. 2.

FIG. 10 is a flowchart illustrating still another process of thepersonal computer in FIG. 2.

FIG. 11 is a block diagram showing another example of the personalcomputer in FIG. 1.

FIG. 12 is a block diagram showing another example of the PDA in FIG. 1.

FIG. 13 is a flowchart illustrating a process of the PDA in FIG. 12.

FIG. 14 is a flowchart illustrating a process of the personal computerin FIG. 11.

FIG. 15 is a flowchart illustrating another process of the personalcomputer in FIG. 11.

FIG. 16 is an illustration of examples of information transmitted andreceived between the personal computer and the PDA.

FIG. 17 is a block diagram showing still another example of the personalcomputer in FIG. 1.

FIG. 18 is a block diagram showing still another example of the PDA inFIG. 1.

FIG. 19 is a flowchart illustrating the PDA in FIG. 18.

FIG. 20 is a flowchart illustrating a process of the personal computerin FIG. 17.

FIG. 21 is a flowchart illustrating another process of the personalcomputer in FIG. 17.

FIG. 22 is a flowchart continued from FIG. 21 which illustrates theother process of the personal computer in FIG. 17.

FIG. 23 is an illustration of an example of a communication system.

FIG. 24 is a block diagram showing an example of the communication unitin FIG. 23.

FIG. 25 is a flowchart illustrating the operation of the communicationsystem in FIG. 23.

FIG. 26 is a flowchart illustrating another operation of thecommunication system in FIG. 23.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is an illustration of an example of a communication system towhich the present invention is applied.

When a PDA (Personal Digital Assistants) 11 is brought close to apersonal computer 1, the personal computer 1 acquires information storedon an IC tag 12 of the PDA 11 by using electromagnetic waves radiatedfrom a reader 2, as indicated by the dashed line in FIG. 1.

As the information stored on the IC tag 12, the personal computer 1acquires, for example, a device ID such as an IP address or a Bluetooth™address which is uniquely set in the PDA 11.

The personal computer 1 restricts access by using the device ID acquiredby the reader 2.

Specifically, the personal computer 1 and the PDA 11 includecommunication units (a communication unit 29 (see FIG. 2), and acommunication unit 89 (see FIG. 4)) that perform wired or wirelesscommunication, respectively. When the PDA 11 requests the personalcomputer 1 to perform communication using its communication unit, thepersonal computer 1 requests the PDA 11 to first transmit the device ID.

In response to this request, the PDA 11 transmits its device ID to thepersonal computer 1 from the communication unit 89.

When receiving the device ID transmitted from the PDA 11, the personalcomputer 1 determines whether or not the received device ID is identicalto that acquired beforehand by the reader 2. If the personal computer 1has determined that the received device ID is identical, it allowscommunication by the communication 29, that is, a connection.

Accordingly, if another device other than the PDA 11 requests aconnection to the personal computer 1, since the device ID is notrecorded in the personal computer 1 beforehand, the device cannotcommunicate with the personal computer 1.

By way of example, when the personal computer 1 is installed as a serverfor delivering predetermined information in an event place, personsgathering in the place simply bring their own devices (device havingbuilt-in tags) close to the personal computer 1, whereby, after that,they can access the personal computer 1 and can acquire information. Inother words, persons who do not bring their own devices close thepersonal computer 1 cannot access the personal computer 1, and cannotacquire any information.

FIG. 2 is a block diagram showing an example of the personal computer 1in FIG. 1.

A CPU (Central Processing Unit) 21 executes various processes inaccordance with programs stored in a ROM (Read Only Memory) 22 or astorage unit 28. A RAM 23 stores a program executed by the CPU 21 anddata, if necessary. The CPU 21, the ROM 22, and RAM 23 are connected toone another by a bus 24.

An input/output interface 25 is connected to the bus 24, and the reader2 for reading information from the IC tag 12 built into the PDA 11, asdescribed above, and for example, a display unit 26 including an LCD(Liquid Crystal Display), an input unit 27 including a keyboard and amouse which are used by a user, and the storage unit 28, which includesa hard disk, are connected to the input/output interface 25.

Also, a communication unit 29 that communicates with various devices,for example, by means of wireless communication such as Bluetooth andwireless LAN (Local Area Network) or by wired communication is connectedto the input/output interface 25.

A drive 30 is also connected to the input/output interface 25. In thedrive 30, a magnetic disk 31, an optical disk 32, a magneto-optical disk33, a semiconductor memory 34, etc., can be loaded, if required. Aprogram, read from the magnetic disk 31 to the semiconductor memory 34,is supplied through the input/output interface 25 and is stored in, forexample, the storage unit 28.

FIG. 3 is a block diagram showing a detailed example of the reader inFIG. 2.

An IC 41 includes a CPU 61, a ROM 62, a RAM 63, an SCC (SerialCommunication Controller) 64, an SPU (Signal Processing Unit) 66, and abus 65 connecting the CPU 61 to the SPU 66 to one another.

The CPU 61 loads a control program stored in the ROM 62 into the RAM 63,and executes various processes based on control signals supplied fromthe CPU 21 in FIG. 2. For example, when a device ID is transmitted fromthe IC tag 12 of the PDA 11, the CPU 61 supplies it to the CPU 21.

The SCC 64 uses the bus 65 to supply the CPU 61 with data supplied fromthe CPU 21 in FIG. 2, and outputs, to the CPU 21, data supplied throughthe bus 65.

When being supplied with predetermined data by the demodulator 44, theSPU 66 performs BPSK (Binary Phase Shift Keying) demodulation (decodingto Manchester codes) on the data, and supplies the obtained data to theCPU 61. Also, when a command to be transmitted to the PDA 11 is suppliedby the bus 65, the SPU 66 performs BPSK modulation (coding to Manchestercodes) on the command, and outputs the obtained data to the modulator42. In other words, the reader 2 can write predetermined information onthe IC tag 12 of the PDA 11, if required.

The modulator 42 performs, based on data supplied form the SPU 66, ASK(Amplitude Shift Keying) on a carrier which is supplied from theoscillator circuit 43 and which has a predetermined frequency (e.g.,13.5 MHz), and outputs the generated modulated waves as electromagneticwaves from the antenna 45. The demodulator 44 demodulates modulatedwaves (ASK modulated waves) acquired by the antenna 45, and outputs thedemodulated data to the SPU 66.

The antenna 45 radiates predetermined electromagnetic waves, detects,based on a change in load thereon, for example, the IC tag 12 of the PDA11, and receives (reads) various types of data.

FIG. 4 is a block diagram showing an example of the PDA 11.

Since a CPU 81 to the communication unit 89 are basically similar to theCPU 21 to the communication unit 29 in the personal computer 1, detaileddescriptions thereof are omitted, accordingly.

Based on a control program stored in the ROM 82, etc., the CPU 81controls the operation of the entirety of the PDA 11, and manages theinformation stored on the IC tag 12 so that, for example; a device IDcan be provided to the personal computer 1.

The CPU 81 stores, for example, in a storage unit 88, an ID identical tothe device ID stored in the IC tag 12 so that the device ID of the PDA11 can be transmitted to the personal computer 1 when the CPU 81controls the communication unit 89 to access the personal computer 1.

Similarly to the communication unit 29 of the personal computer 1, thecommunication unit 89 communicates with various devices by wireless,such as Bluetooth or wireless LAN or by wire.

FIG. 5 is a block diagram showing an example of the IC tag 12 in FIG. 4.

The IC tag 12 includes, for example, an antenna 112 and an IC 111 inwhich components other than that are accommodated in a single chip, anduses electromagnetic induction to perform half-duplex communicationusing various types of data with, for example, the reader 2 of thepersonal computer 1. Those having a function similar to that of the ICtag 12 include, for example, Felica (registered trademark).

A CPU 121 controls, based on a control program stored in a ROM 122, theoperation of the entirety of the IC tag 12.

When data demodulated by an ASK demodulator 129 has a BPSK modulatedform, an SPU 126 performs demodulation (Manchester code decoding) on thedata based on a clock signal supplied from a PLL unit, which is notshown, and outputs the demodulated data to the CPU 121, etc., through abus 125, if required.

The SPU 126 performs BPSK modulation (coding to Manchester codes) ondata supplied through the bus 125, and outputs the modulated data to anASK modulator 127.

When transmitting, for example, data such as a device ID to the reader 2of the personal computer 1, the ASK modulator 127 turns on/off apredetermined switching element in response to data supplied from theSPU 126. Only when the switching element is in on-state does the ASKmodulator 127 change the load on the antenna 112 by connecting apredetermined load in parallel to the antenna 112.

The change in the load on the antenna 112 causes the ASK modulator 127to perform ASK modulation on modulated waves from the reader 2 which arebeing received by the antenna 112 and to transmit (change a terminalvoltage of the antenna 45 of the reader 2) the modulated component tothe reader 2 through the antenna 112.

The ASK demodulator 129 uses envelope detection to demodulate modulatedwaves (ASK modulated waves) received by the antenna 112, and outputs thedemodulated data to the SPU 126. The antenna 112 resonates due to, forexample, electromagnetic waves having a predetermined frequency whichare radiated from the reader 2.

After rectifying an alternating current magnetic field excited by theantenna 112, and stabilizing the obtained current, a power-supplygenerator 130 supplies the current as a direct-current power supply toeach component.

Next, the operation of the communication system in FIG. 1 is described.

At first, a process of the personal computer 1 which acquires an deviceID from the PDA 11 and registers the device ID is described withreference to the flowchart in FIG. 6.

In step S1, based on an output from the reader 2, the CPU 21 determineswhether or not it has read an device ID from the IC tag 12 of the PDA11, and is on standby until it determines that it has read.

For example, the reader 2 always radiates electromagnetic waves fordetecting the IC tag 12, and reads the device ID of the PDA 11 which isstored on the IC tag 12 (PDA 11) when the IC tag 12 is, brought close tothe reader 2

When the CPU 21 determines in step S1 that it has read the device ID, itproceeds to step S2, and registers the device ID of the PDA 11 on aconnection permission list.

The connection permission list is a list of device IDs read by thereader 2 and is stored in the storage unit 28. Only devices having thedevice IDs registered on the list can connect to (access) thecommunication unit 29.

After that, the process returns to step S1, and the subsequentprocessing is repeatedly executed.

Next, a process of the PDA 11 which registers a device ID in thepersonal computer 1 is described with reference to the flowchart in FIG.7.

In step S11, the CPU 121 of the IC tag 12 determines whether or not theIC tag 12 is positioned nearby to the reader 2, and is on standby untilthe CPU 121 determines that the IC tag 12 is positioned nearby.

As described above, since the electromagnetic waves for detecting the ICtag 12 are radiated from the reader 2, when the waves are received bythe antenna 112, the CPU 121 determines in step S1 that the IC tag 12 ispositioned close to the reader 2. Proceeding to step S12, the CPU 112provides the device ID stored in the flash memory 124.

The provided device ID is received by the reader 2 of the personalcomputer 1, and is registered on the connection permission list.

After that, the process returns to step S11, and repeatedly executes thesubsequent processing.

Next, a process of the PDA 11 which connects to the personal computer 1(the communication unit 29) is described with reference to the flowchartin FIG. 8.

In step S21, based on an output from the input unit 87, the CPU 81determines whether or not the PDA 11 is instructed to connect to thepersonal computer 1 by the user and is on standby until it determinesthat the PDA 11 is instructed.

When determining in step S21 that the PDA 11 is instructed to connect tothe personal computer 1, the CPU 81 proceeds to step S22, and controlsthe communication unit 89 to access the personal computer 1 and totransmit the device ID of the PDA 11.

When the storage unit 88 stores, for example, an address forcommunicating with the personal computer 1, communication-methodidentifying information (communication information), etc., the CPU 81accesses the personal computer 1 based thereon, and transmits the deviceID from the communication unit 89. Obviously, information for accessingthe personal computer 1 may also be input by the user.

The device ID transmitted from the communication unit 89 by wireless orby wire is received by the communication unit 29 of the personalcomputer 1. It is determined whether or not the device ID is registeredon the connection permission list.

In step S23, based on the information received by the communication unit89, the CPU 81 determines whether or not the personal computer 1 hasnotified the PDA 11 of permission of the link.

When determining in step S23 that the personal computer 1 has notnotified the personal computer 1 of permission of the connection (theconnection is rejected), the CPU 81 returns to step S21 and repeatedlyexecutes the subsequent processing.

When conversely determining in step S23 that the personal computer 1 hasnotified the PDA 11 of permission of the connection, the CPU 81 proceedsto step S24, and controls the communication unit 89 to establishcommunication with the personal computer 1 and to transmit and receivepredetermined information. After that, the process returns to step S21,and the subsequent processing is repeatedly executed.

Next, a process of the personal computer 1 which is executedcorrespondingly to the process in FIG. 8 is described with reference tothe flowchart in FIG. 9.

In step S31, based on an output from the communication unit 29, the CPU21 determines whether or not a connection to the personal computer 1 isrequested by the PDA 11, and is on standby until the CPU 21 determinesthat a connection to the personal computer 1 is requested.

When determining in step S31 that the connection to the personalcomputer 1 is requested, the CPU 21 proceeds to step S32, and acquiresthe device ID received by the communication unit 29. As is describedwith reference to the flowchart in FIG. 8, when a connection to thepersonal computer 1 is requested, the device ID of the PDA 11 istransmitted from the PDA 11.

In step S33, by referring to the connection permission list stored inthe storage unit 28, the CPU 21 determines whether or not thetransmitted device ID is registered on the connection permission list,that is, whether to permit the connection.

When determining in step S33 that the transmitted device ID is notregistered on the connection permission list, the CPU 21 proceeds tostep S34, and notifies the device having transmitted the device ID thatthe personal computer 1 cannot permit the connection.

When conversely determining in step S33 that the transmitted device IDis not registered on the connection permission list, the CPU 21 proceedsto step S35, and controls the communication unit 29 to notify the PDA 11that the personal computer 1 permits the connection. For example thedevice ID of the PDA 11 is registered as described above the PDA 11 isnotified that the connection is permitted.

In step S36, communication is established, for example, with the PDA 11,to which a connection is permitted, and predetermined information istransmitted and received.

Since the IC tag 12 is used to provide the device ID, as describedabove, the user (user who wishes a connection to the personal computer1) of the PDA 11 can register the device ID by simply bringing the PDA11 close to the personal computer 1.

Also, only devices having device IDs registered on the connectionpermission list are permitted to connect. Thus, users who do not bringtheir devices close to the personal computer 1 can be prevented fromaccessing the personal computer 1.

Next, a process of the personal computer 1 which manages the device IDsregistered on the connection permission list is described with referenceto the flowchart in FIG. 10.

In step S51, the CPU 21 refers to the connection permission list anddetermines whether or not the connection permission list includes adevice ID in which a predetermined time has passed since itsregistration.

When determining in step S51 that the connection permission list doesnot include any device ID in which the predetermined time has passed,the CPU 21 repeatedly executes the subsequent processing. Conversely,when determining that the connection permission list includes a deviceID in which the predetermined time has passed, the CPU 21 proceeds tostep S52 and deletes the device ID.

Accordingly, even a user who brought his or her device close to thepersonal computer 1 and registered its device ID in the past cannotestablish a connection to the personal computer 1 after a certain timepasses since the device ID is registered. Therefore, regardingpermission of a connection, also temporal restriction can be set.

In the foregoing, the personal computer 1 is provided with the reader 2,and the PDA 11 is provided with the IC tag 12. Conversely, also byproviding the personal computer 1 with an IC tag IC tag 141 (see FIG.11), and providing the PDA 11 with a reader (reader 151 (see FIG. 12),connections from various devices can be restricted.

For example, in this case, an IC tag 141 of the personal computer 1stores information (communication information) such as the address ofthe personal computer 1 and a URL (Uniform Resource Locator), and apassword. When being positioned close to the personal computer 1, areader 151 of the PDA 11 reads the information from the IC tag 141.

When being instructed to connect to the personal computer 1, the PDA 11uses the address read by the reader 151 to access the personal computer1 and transmits the password.

The personal computer 1 determines whether or not the transmittedpassword is identical to a password provided by the IC tag 141. Whendetermining that both are identical, the personal computer 1 permits thePDA 11 to connect.

Accordingly, similarly to the above-described case, only a user whobrings his or her device (a device in which the reader 151 is provided)can access the personal computer 1.

FIG. 11 is a block diagram showing another example of the personalcomputer 1 in which the IC tag 141 is provided.

Since the CPU 21 to semiconductor memory 34 shown in FIG. 11 areidentical to those shown in FIG. 2, detailed description thereof areomitted, if required.

In order that information, such as an address, and a password, may beprovided to the PDA 11 in a close position, the CPU 21 stores theinformation in the IC tag 141. Also, the CPU 21 uses, for example, thestorage unit 28 to store a password identical to the password stored onthe IC tag 141 so that the CPU 21 can determine whether or not thepassword posted from the communication unit 29 through the FDA 11 isvalid.

When the reader 151 of the PDA 11 is positioned nearby and the radiatedelectromagnetic waves are received, the IC tag 141 provides the reader151 with the information, such as the address of the personal computer1, and the password. The IC tag 141 is similar in structure to the ICtag 12 shown in FIG. 5, and the information, such as the address of thepersonal computer 1, and the password, are stored in a flash memory.

FIG. 12 is a block diagram showing an example of the PDA 11, in whichthe reader 151 is provided.

Since the CPU 81 to communication unit 89 shown in FIG. 12 are identicalto those shown in FIG. 4, detailed descriptions thereof are omitted,accordingly.

When being positioned close to the personal computer 1 and detecting theIC tag 141, the reader 151 reads and supplies, to the CPU 81, theinformation, such as the address, and the password which are stored onthe IC tag 141

Next, a process of the PDA 11 which establishes, based on theinformation read from the IC tag 141, a connection to the personalcomputer 1 is described with reference to the flowchart in FIG. 13.

In step S61, based on an output from the reader 151, the CPU 81determines whether or not data has been read from the IC tag 141, and ison standby until the CPU 81 determines that the data has been read.

When the PDA 11 is brought close to the personal computer 1, the datastored on the IC tag 141 is read and supplied to the CPU 81 by thereader 151.

When determining in step S61 that the data has been read from the IC tag141, the CPU 81 proceeds to step S62, and extracts the address andpassword of the personal computer 1 from the read data.

The extracted address and password are stored, for example, in the RAM82 or the storage unit 88 in step S63.

In step S64, the CPU 81 determines whether or not the PDA 11 isinstructed by the user to connect to the personal computer 1, and is onstandby until the CPU 81 determines that the PDA 11 is instructed.

When determining in step S64 that the PDA 11 is instructed to connect tothe personal computer 1, the CPU 81 proceeds to step S65, and accessesthe personal computer 1 by controlling the communication unit 89 basedon the information such as the address which is read by the reader 151and is stored.

In step S66, the CPU 81 determines whether or not the PDA 11 isrequested to transmit a password by the personal computer 1, and is onstandby until the CPU 81 determines that the PDA 11 is requested.

When determining in step S66 that the PDA 11 is requested to transmitthe password, the CPU 81 proceeds to step S67, and transmits the storedpassword from the communication unit 89 to the personal computer 1.

In step S68, the CPU 81 determines whether or not the PDA 11 ispermitted to connect. If the CPU 81 has determined that the PDA 11 isnot permitted to connect, it returns to step S61 and repeatedly executesthe subsequent processing.

As described later, the personal computer 1 determines whether or not apassword transmitted from the PDA 11 is identical to a password managedby the personal computer 1. Only when it is determined that both areidentical does the personal computer 1 permit the PDA 11 to connect.

In step S68, alternatively, if the CPU 81 has determined that the PDA 11is permitted to connect, it proceeds to step S69, and establishes aconnection and uses the communication unit 89 to transmit and receivevarious types of information.

Next, a process of the personal computer 1 which is executedcorrespondingly to the process in FIG. 13 is described with reference tothe flowchart in FIG. 14.

In step S81, a CPU of the IC tag 141 determines whether or not thereader 151 of the PDA 11 is positioned nearby, and is on standby untilthe CPU determines that the reader 151 is positioned nearby.

When determining in step S81 that the reader 151 of the PDA 11 ispositioned nearby, the CPU of the IC tag 141 proceeds to step S82, andprovides the PDA 11 (the reader 151) with the information, such as theaddress, and the password which are stored in the flash memory.

In step S83, based on an output from the communication unit 29, the CPU21 determines whether or not a connection to the personal computer 1 isrequested to the PDA 11 thereby, and is on standby until the CPU 21determines that the connection to the personal computer 1 is requested.

When determining in step S83 that the connection to the personalcomputer 1 is requested by the PDA 11, the CPU 21 proceeds to step S84,and requests the PDA 11 to transmit a password.

In step S85, the CPU 21 determines whether or not the password has beentransmitted, and is on standby until the CPU 21 determines that thepassword has been transmitted. As described with reference to theflowchart in FIG. 13, in response to this request, the password providedby the IC tag 141 is transmitted from the PDA 11.

When determining in step S85 that the password has been transmitted, theCPU 21 proceeds to step S86, and determines whether or not thetransmitted password is identical to the password (a password identicalto that provided from the IC tag 141) stored in the storage unit 28 orthe like, that is, whether or not the password is valid. Whendetermining in step S85 that the password is not valid, the CPU 21proceeds to step S87 and notifies the PDA 11 that the personal computer1 cannot permit the PDA 11 to connect. After that, the process returnsto step S81, and repeatedly execute the subsequent processing.

In step S86, alternatively, if the CPU 21 has determined that thepassword is valid, it proceeds to step S88, and notifies the PDA 11 thatthe personal computer 1 permits the PDA 11 to connect.

After that, in step S89, the connection is established and thecommunication unit 29 is used to transmit and receive various types ofinformation.

As described above, for example, also by providing the personal computer1 with the IC tag 141, and providing the PDA 11 with the reader 151,links from those other than users who bring their devices close to thepersonal computer 1 can be restricted.

In addition, it can be determined, based on a password, whether or not auser who brings a device close to the personal computer 1 requests aconnection to the personal computer 1. Thus, even if a user who does notbring a device close to the personal computer 1 acquires an address orthe like, only it does not enable the user to establish a connection tothe personal computer 1.

Next, a process of the personal computer 1 which manages the passwordstored on the IC tag 141 is described with reference to the flowchart inFIG. 15.

In step S101, the CPU 21 determines whether or not a predetermined timehas passed, and is on standby until the CPU 21 determines that the timehas passed. When determining in step S102 that the predetermined timehas passed, the CPU 21 proceeds to step S102, and changes the passwordstored in the flash memory of the IC tag 141.

After that, the process returns to step S101, and repeatedly executesthe subsequent processing.

Accordingly, similarly to the process described with reference to FIG.10, for a user who has acquired a password or the like by bringing hisor her own device close to the personal computer 1, it is impossible toestablish a connection to the personal computer 1 after a certain timehas passed since registration.

In the above example, for the personal computer 1 and the PDA 11, eithera reader or an IC tag is provided. By providing both, it is more ensuredthat connections from various devices are restricted.

FIG. 16 is a schematic illustration of the personal computer 1 and PDA11 shown in FIG. 1, and shows examples of information transmitted andreceived as electromagnetic waves when both devices are provided with ICtags and readers.

When the personal computer 1 and the PDA 11 are positioned close to eachother, as shown in FIG. 16, the device ID of the PDA 11 is transmitted(read by the reader 2) from the IC tag 12 of the PDA 11 to the reader 2of the personal computer 1.

Also, from the IC tag 141 of the personal computer 1, information suchas an address which is necessary for a connection, and a password aretransmitted (read by the reader 151) to the reader 151 of the PDA 11.

Based on the pieces of information, the connection to the personalcomputer 1 is restricted.

Specifically, the device ID acquired by the personal computer 1 isregistered on a connection permission list as described above, and whena connection to the PDA 11 is actually requested, it is determinedwhether or not the device ID transmitted from the PDA 11 is registeredon the connection permission list. The address acquired by the PDA 11 isused for the PDA 11 to access the personal computer 1. The password istransmitted to the personal computer 1, and it is determined whether ornot the password is identical to the password managed by the personalcomputer 1.

Only a device which has a device ID registered on the connectionpermission list and which has transmitted a password identical to apassword provided by the personal computer 1 is permitted to connect tothe personal computer 1.

FIG. 17 is a block diagram showing an example of the personal computer1, in which the reader 2 and the IC tag 141 are provided.

The structure shown in FIG. 17 is a combination of the structures shownin FIG. 2 and FIG. 17.

In other words, the device ID of the PDA 11 which is read by the reader2 is transferred to, for example, the storage unit 28, and is registeredon the connection permission list.

The IC tag 141 stores information (communication information) such as anaddress which is necessary for another device to connect to the personalcomputer 1. The information is read by the reader 151 of the PDA 11.

The storage unit 28, or the like, stores a password identical to apassword stored on the IC tag 141, and the password is used to determineidentity with the password received by the communication unit 29.

FIG. 18 is a block diagram showing an example of the PDA 11, in whichthe IC tag 12 and the reader 151 are provided.

The structure shown in FIG. 18 is a combination of the structures shownin FIG. 4 and FIG. 12.

In other words, the device ID of the PDA 11 is stored on the IC tag 12and is read by the reader 2 of the PDA 11. Also, an ID that is identicalto the device ID stored on the IC tag 12 is provided also in the storageunit 88 or the like, and is transmitted from the communication unit 89to the personal computer 1.

The reader 151 reads and supplies, to the CPU 81, the address and thepassword from the IC tag 141 of the personal computer 1. The password istransmitted from the communication unit 89 to the personal computer 1and is used for authentication.

Next, a process of the PDA 11 which connects to the personal computer 1is described with reference to the flowchart in FIG. 19.

This process is a combination of the processes described with referenceto FIG. 7, FIG. 8, and FIG. 13.

In other words, processing from step S111 to step S113 is similar tothat from step S61 to step S63 in FIG. 13.

In step S111, based on an output from the reader 151, the CPU 81determines whether or not the reader 151 has read data from the IC tag141 of the personal computer 1. If the CPU 81 has determined that thereader 151 has read data, it proceeds to step S112. In step S112, theCPU 81 extracts the address and password of the personal computer 1 fromthe data read from the reader 151.

The extracted address and password are stored, for example, in the RAM82 or the storage unit 88 in step S113.

In step S114, similarly to step S12 in FIG. 12, the CPU 81 provides thereader 2 of the personal computer 1 with the device ID stored on the ICtag 12. In other words, the reader 2 reads the device ID.

In step S115, the CPU 81 determines whether or not the PDA 11 isinstructed to connect to the personal computer 1, and is on standbyuntil the CPU 81 determines that the PDA 11 is instructed.

When determining in step S115 that the PDA 11 is instructed to connectto the personal computer 1, the CPU 81 proceeds to step S116, andaccesses the personal computer 1 based on the stored information such asthe address, and transmits the device ID from the communication unit 89.

The personal computer 1 determines whether or not the transmitted deviceID is registered on the connection permission list. The PDA 11 isnotified of the result.

In step S117, the CPU 81 determines whether or not the personal computer1 has notified the PDA 11 that the transmitted device ID is registeredon the connection permission list. If the CPU 81 has determined that thepersonal computer 1 has not notified the PDA 11 (determination of noregistration has been posted), the CPU 81 proceeds to step S111 andrepeatedly executes the subsequent processing.

In step S117, alternatively, if the CPU 81 has determined that personalcomputer 1 has notified the PDA 11 of the determination that the deviceID is registered on the connection permission list, the CPU 81 proceedsto step S181.

Processing from step S118 to step S121 is similar to that from step S66to step S69 in FIG. 13.

In step S118, the CPU 81 determines whether or not the PDA 11 isrequested by the personal computer 1 to transmit the password, and is onstandby until the CPU 81 determines that the CPU 81 is requested.

When determining in step S118 that the PDA 11 is requested to transmitthe password, the CPU 81 proceeds to step S119, and transmits the storedpassword from the communication unit 89 to the personal computer 1.

In step S120, the CPU 81 determines whether or not the personal computer1 has permitted the PDA 11 to connect. If the CPU 81 has determined thatthe personal computer 1 has not permitted, it returns to step S111, andrepeatedly executes the subsequent processing. Conversely, if the CPU 81has determined that the personal computer 1 has permitted the PDA 11, itproceeds to step S121, and establishes a connection and uses thecommunication unit 89 to transmit and receive information.

Next, a process of the personal computer 1 which is executedcorrespondingly to the process in FIG. 19 is described with reference tothe flowchart in FIG. 20.

The process shown in FIG. 20 is basically a combination of the processesdescribed with reference to FIG. 6, FIG. 9, and FIG. 14.

In step S131, a CPU of the IC tag 141 determines whether the reader 151of the PDA 11 is positioned nearby. If the CPU has determined that thereader 151 is positioned nearby, it proceeds to step S132, and providesthe PDA 11 (the reader 151) with the information stored in the flashmemory, such as the address, and the password.

In step S133, the CPU 21 controls the reader 2 to read the device IDstored on the IC tag 12 of the PDA 11. The CPU 21 proceeds to step S134,and registers the device ID on the connection permission list.

In step S135, the CPU 21 determines whether or not a connection to thepersonal computer 1 is requested by the PDA 11. If the CPU 21 hasdetermined that the personal computer 1 is requested, it proceeds tostep S136 and acquires the device ID transmitted from the PDA 11.

In step S137, by referring to the connection permission list, the CPU 21determines whether or not the transmitted device ID is registered on theconnection permission list, that is, whether or not to permit the PDA 11to connect.

When determining in step S137 that the transmitted device ID is notregistered on the connection permission list, the CPU 21 proceeds tostep S138, and notifies the device having transmitted the device ID thata connection cannot be permitted. After that, the process returns tostep S131 and repeatedly executes the subsequent processing.

Conversely, when determining in step S137 that the transmitted device IDis registered on the connection permission list, the CPU 21 proceeds tostep S139, and notifies the PDA 11 that the device ID is registered onthe connection permission list.

Processing from step S140 to step S144 is similar to processing in step84 to step 86, step S88, and step S89.

Specifically, in step S140, the CPU 21 requests the PDA 11 to transmit apassword.

In step S141, the CPU 21 determines whether or not the password istransmitted. If the CPU 21 has determined that the password istransmitted, it proceeds to step S142.

In step S142, by referring to the password provided from the IC tag 141,the CPU 21 determines whether or not the transmitted password is valid.If the CPU 21 has determined that the transmitted password is not valid,it proceeds to step S138, and notifies the PDA 11 that the personalcomputer 1 cannot permit the PDA 11 to connect.

When conversely determining in step S142 that the password is valid, theCPU 21 proceeds to step S143 and notifies the PDA 11 that the personalcomputer 1 permits the PDA 11 to connect.

After that, in step S144, the connection between the personal computer 1and the PDA 11 is established and various types of information aretransmitted and received.

As described above, also by providing each of the personal computer 1and the PDA 11 with an IC tag and a reader, connections from those otherthan a user who brings a device close to the personal computer 1 can berestricted, and authentication therefor (determination of whether or notthe device is permitted to connect) is more complex, thus enablingunauthorized connections.

The above has mainly described a case in which the PDA 11 requests aconnection, to the personal computer 1 and the personal computer 1authenticates the PDA 11. However, obviously, the personal computer 1may conversely request a connection to the PDA 11. In this case, notonly the PDA 11 authenticates the personal computer 1 by executing theabove process of the personal computer 1, but also both the personalcomputer 1 and PDA 11 authenticate each other, whereby it may bedetermined whether or not each is permitted to connect.

Next, a process in a case in which each of the personal computer 1 andthe PDA 11 is provided with a reader and an IC tag and either one canrequest the other one is described with reference to the flowcharts inFIG. 21 and FIG. 22. Although FIG. 21 and FIG. 22 show a process of thepersonal computer 1, the PDA 11 also performs a similar process.

In step S151, the CPU 21 determines, based on an output from the reader2, whether or not the reader 2 has read data from the IC tag 12 of thePDA 11, and is on standby until the CPU 21 determines that the reader 2has read. When the PDA 11 is brought close, and the CPU 21 determines instep S151 that the PDA 11 has read the data, it proceeds to step S152,and extracts the device ID and address of the PDA 11 which are stored onthe IC tag 12 of the PDA 11.

In step S153, the CPU 21 provides the PDA 11 with the device ID andpassword of the personal computer 1 which are stored on the IC tag 141.In other words, the reader 151 of the PDA 11 is used to read data storedon the IC tag 141.

In step S154, the CPU 21 compares the device ID of the personal computer1 and the device ID of the PDA 11 read from the IC tag 12. When thedevice IDs each consist of a number having predetermined digits, it isdetermined whether or not the device ID of the personal computer 1 isgreater.

In the process in FIG. 21 and FIG. 22, the device IDs are used todetermine which device of the personal computer 1 and PDA 11 is torequest a connection to the other. One device in which a greater deviceID is set can request a connection to the other device.

In other words, when determining in step S154 that the device ID of thepersonal computer 1 is greater, the CPU 21 proceeds to step S155, anddetermines whether or not a connection to the personal computer 1 isrequested by the user.

When determining in step S155 that the connection to the personalcomputer 1 is requested, the CPU 21 proceeds to step S156, and accessesthe PDA 11 based on the address acquired from the IC tag 12 of the PDA11 and requests a connection to the PDA 11.

In step S157, the CPU 21 determines whether or not the personal computer1 is requested by the PDA 11 to transmit the password provided from thePDA 11, and is on standby until the CPU 21 determines that the personalcomputer 1 is requested.

When determining in step S157 that the personal computer 1 is requestedto transmit the password, the CPU 21 proceeds to step S158, andtransmits the password acquired from the IC tag 12 of the PDA 11 fromthe communication unit 29. The PDA 11 performs authentication(determination of whether or not the transmitted password is identicalto the password provided by the PDA 11) based on the transmittedpassword, and posts the result.

In step S159, the CPU 21 determines whether or not the password isauthenticated (whether or not the communication unit 29 has received anotification of authentication). If the CPU 21 has determined that thepassword has not been authenticated, it returns to step S151 since thePDA 11 refuses the connection, and executes the subsequent processing.

When conversely determining in step S159 that the password isauthenticated, the CPU 21 proceeds to step S160, and conversely requeststhe PDA 11 to transmit the password read from the IC tag 141.

In step S161, the CPU 21 determines whether or not the PDA 11 hastransmitted the password, and is on standby until the CPU 21 determinesthat the PDA 11 has transmitted the password.

When determining in step S161 that the password has been transmitted,the CPU 21 proceeds to step S162, and determines whether or not thetransmitted password is valid. Specifically, the CPU 21 determineswhether or not the password received by the communication unit 29 isidentical to the password provided by the IC tag 141.

When determining in step S162 that the password transmitted from the PDA11 is not valid, the CPU 21 proceeds to step S163, and notifies the PDA11 of authentication failure and stops the connection to the PDA 11.After that, the CPU 21 returns to step S151, and executes the subsequentprocessing.

When determining in step S162 that the password is valid, the CPU 21proceeds to step S164, and notifies the PDA 11 of authenticationsuccess. In step S165, the CPU 21 establishes the connection to the PDA11. After that, predetermined information is transmitted and receivedbetween the personal computer 1 and the PDA 11.

In step S154, conversely, if the CPU 21 has determined that the deviceID of the personal computer 1 is not greater than (less than) the deviceID read from the IC tag 12 of the PDA 11, it proceeds to step S166.

This case causes the PDA 11 to request a connection to the personalcomputer 1. In step S166, the CPU 21 determines whether or not the PDA11 has requested the connection to the personal computer 1, and is onstandby until the CPU 21 determines that the PDA 11 has requested aconnection to the personal computer 1.

When determining in step S166 that the PDA 11 has requested theconnection to the personal computer 1, it proceeds to step S167, andrequests the PDA 11 to transmit the password (the password provided fromthe personal computer 1) read from the IC tag 141.

In step S168, the CPU 21 determines whether or not the PDA 11 hastransmitted the password, and is on standby until the PDA 11 hastransmitted the password. When determining in step S168 that the PDA 11has transmitted the password, the CPU 21 proceeds to step S169, anddetermines, by confirming the password transmitted from the PDA 11 andthe password provided from the IC tag 141, whether or not thetransmitted password is valid (whether or not both passwords areidentical).

When determining in step S169 that the password is not valid, the CPU 21proceeds to step S170, and notifies the PDA 11 of authenticationfailure. After that, the process returns to step S151, and repeatedlyexecutes the subsequent processing.

When conversely determining that the password is valid, the CPU 21notifies the personal computer 1 of authentication success in step S171,and proceeds to step S172. The CPU 21 uses the communication unit 29 totransmit the password read from the IC tag 12 of the PDA 11.

The PDA 11 performs authentication based on the transmitted password,and notifies the personal computer 1 of the result.

In step S173, the CPU 21 determines whether or not the PDA 11 hasauthenticated the password. If the CPU 21 has determined that the PDA 11has not authenticated the password, it returns to step S151, andrepeatedly executes the subsequent processing.

When determining in step S173 that the PDA 11 has authenticated thepassword, the CPU 21 proceeds to step S174 The CPU 21 establishes aconnection to the PDA 11, and transmits and receives various types ofinformation.

As described above, based on device IDs, by determining device thatinitiates connection requests, the connection requests can be preventedfrom conflicting.

Obviously, even if each of the personal computer 1 and the PDA 11 isprovided with readers and IC tags, both devices are controlled toexecute device ID management as described with reference to FIG. 10, andalso to execute password change as described with reference to FIG. 15,etc.

In the foregoing, the reader 2 (IC tag 141) of the personal computer 1and the IC tag 12 (reader 151) of the PDA 11 are used to transmit andreceive information such as a device ID, an address, and a password inthe form of electromagnetic waves. However, in a case in which thefunction is achieved by bringing both devices close to each other, forexample, various communication methods such as, for example, IrDA can beused.

Although in the foregoing the tag and the reader are constituted byseparate modules, both may be constituted by a single module.

In the foregoing, establishment of communication by Bluetooth isperformed based on, for example, information such as device IDs which istransmitted and received between the reader 2 provided in the personalcomputer 1 and the IC tag 12 provided in the PDA 11. However, even ifthe personal computer 1 and the PDA 11 each are not provided with amodule that uses electromagnetic induction to perform short distancewireless communication, by controlling the output power of radio wavesfrom a communication unit (e.g., the communication unit 89 of the PDA11), communication can be initiated only between close devices.

A communication system that specifies another terminal in communicationand initiates communication between close devices by controlling theoutput power of radio waves output from a wireless communication unit isdescribed below.

FIG. 23 is an illustration of an example of the communication system.

By way of example, in the case of specifying another device incommunication using Bluetooth and establishing communication with thedevice, the PDA 11 firstly suppresses the output power of thecommunication unit 89 (e.g., a Bluetooth module) and controls radiatedradio waves to reach for example, within a several centimeter range.

In such a state in which a very weak power mode for suppressing theoutput power of radio waves is set, the communication unit 89 repeatedlyperforms “Inquiry”, and searches for a terminal positioned in a range(e.g., within a several centimeter range) in which the radio wavesreach.

When the PDA 11 is brought close to or put on the personal computer 1 bythe user, and the radio waves radiated by the communication unit 89 arereceived by the communication unit 29 (a module for performingcommunication in accordance with the same specifications as thecommunication unit 89) of the personal computer 1, the communicationunit 29 responds to the Inquiry. Thus, the communication unit 89establishes a communication link by performing “Inquiry, Page” (calling)with the communication unit 29. The established communication link iseffective in a very narrow range reachable by radio waves from thecommunication unit 89 in which the very weak power mode is set.

Accordingly, after the communication unit 89 temporarily breaks thecommunication link and changes the very weak power mode to a normalpower mode in order to enable communication with the communication unit29, even if there is some distance therebetween, the communication unit89 re-establishes a communication link with the communication unit 29,based on already acquired information (information acquired by the“Inquiry, Page” in a short distance).

The re-established communication link is effective in a range of severaltens of meters, etc., in which radio waves reach, similarly tocommunication in accordance with Bluetooth, and enables Bluetoothcommunication, even if the distance between the personal computer 1 andthe PDA 11 is sufficiently large.

As described above, even if the personal computer 1 and the PDA 11 arenot provided with wireless modules using electromagnetic induction, bycontrolling the output power of the communication unit, simply bringingthe PDA 11 close to the personal computer 1 by the user can establishBluetooth communication between those terminals so that various types ofinformation, such as a device ID, an address, and a password, can betransmitted and received.

In other words, in this case, when the PDA 11, in which the very weakpower mode is set, is brought close to the personal computer 1,Bluetooth communication in accordance with the very weak power mode isestablished, and in the communication, for example, a device ID istransmitted from the PDA 11 (the communication unit 89) and isregistered in the personal computer 1 (the communication unit 29).

After that, when the PDA 11 is instructed to connect to the personalcomputer 1 by the user, the normal power mode is set as the power modein the communication unit 89 of the PDA 11, and authentication using adevice ID is performed between the PDA 11 and the personal computer 1 isperformed. Subsequently, Bluetooth communication in accordance with thenormal power mode is established.

Accordingly, even if a plurality of devices that can performcommunication using Bluetooth are positioned around the personalcomputer 1, users who can establish connections to the personal computer1 by using their own device are only those who have recorded the deviceID in the personal computer 1 by bringing their own device close to thepersonal computer 1 and performing communication in accordance with thevery weak power mode.

As described above, in the case of using information such as a passwordin authentication, an address and a password are transmitted andreceived between the personal computer 1 and the PDA 11 when thecommunication in accordance with the very weak power mode isestablished. After that, authentication based on the password isperformed, and when the authentication is completed, communication inaccordance with the normal power mode is initiated.

Also, when the communication in accordance with the very weak power modeis established, an exterior image of a device that initiatescommunication, or an image indicating data to be transferred aretransmitted and received, and are displayed by each device, whereby theuser can confirm processing (e.g., processing performed whencommunication in accordance with the normal power mode is established)beforehand which is performed between two devices between whichcommunication is established.

When the power mode of the communication unit 89 can be seamlesslyswitched, the set power mode may be switched from the very weak powermode to the normal power mode without temporarily breaking thecommunication link established when the very weak power mode is set.

FIG. 24 is a block diagram showing a detailed example of thecommunication unit 89 in FIG. 23.

The communication unit 89 includes a Bluetooth module or a wireless-LANmodule.

A radio controller 201 controls a change-over switch 204. The radiocontroller 201 connects a switch 204A to contact a when transmittinginformation to an external terminal, while it connects the switch 204Ato contact b when receiving information from the external terminal.

Based on control by the CPU 81 which is performed by using theinput/output interface 85 (FIG. 4), the radio controller 201 controls areachable range (output power) of radio waves radiated from an antenna207 by controlling the gain of a power amplifier 205.

Specifically, when being instructed by the CPU 81 to be set to have thevery weak power mode, the radio controller 201 controls the gain of thepower amplifier 205 so that the reachable range of the radio wavesradiated from the antenna 207 is narrowed. Also, when another terminalin communication can be specified and the very weak power mode isinstructed to switch to the normal power mode, the radio controller 201controls the gain of the power amplifier 205 so that the reachable rangeof the output radio waves is broadened.

A baseband controller 202 controls a baseband signal in atransmitted/received signal. A modem processor 203 performs, on anoutput from the baseband controller 202, FGSK modulation processing andspread spectrum processing based on a hopping frequency, and outputs theobtained signal from the antenna 207 through the power amplifier 205.The modem processor 203 performs inverse spread spectrum processing andGFSK demodulation processing on an output from an LNA (Low NoiseAmplifier) 206, and outputs the obtained signal to the basebandcontroller 202.

Since the structure of the communication unit 29 provided in thepersonal computer 1 is similar to that of the communication unit 89shown in FIG. 24, a description thereof is omitted.

As described above, in the communication system shown in FIG. 23, thepersonal computer 1 and the PDA 11 are not provided with a reader, an ICtag, etc.

Next, the operation of the communication system in FIG. 23 is describedwith reference to the flowchart in FIG. 25. FIG. 25 illustratesprocessing which establishes communication in accordance with Bluetoothby using a device ID and which corresponds to FIG. 6 to FIG. 9.

By way of example, when the user instructs the PDA 11 to initiatecommunication in accordance with Bluetooth, the communication unit 89 ofthe PDA 11 is activated based on control by the CPU 81. In step S201,the communication unit 89 sets the very weak power mode therein as itspower mode. The communication unit 89 proceeds to step S202, andsearches for a close terminal by repeatedly executing the Inquiry.

In the Inquiry executed in step S202, an IQ packet (Inquiry packet) isrepeatedly broadcasted in a range of, for example, several centimetersfrom the antenna 207 because the very weak power mode is set to suppressthe reachable range of the radio waves.

In addition, in step S221, the communication unit 29 of the personalcomputer 1 is set to be in a state of repeatedly executing an Inquiryscan and a Page scan, and is on standby until it receives Inquiry andPage requests from another terminal.

When the user brings the PDA 11 close to the personal computer 1, andthe communication unit 29 of the personal computer 1 is positioned inthe reachable range of the radio waves from the communication unit 89 ofthe PDA 11, the IQ packet broadcasted from the communication unit 89 isreceived by the communication unit 29 in step S222.

When receiving the IQ packet broadcasted by the communication unit 89,the communication unit 29 proceeds to step S223, and transmits an FHSpacket to the communication unit 89. The FHS packet includes, as(Bluetooth slave) attribute information of the personal computer 1,information representing the Bluetooth address and Bluetooth clock ofthe personal computer 1.

When receiving the FHS packet transmitted from the communication unit 29in step S203, the communication unit 89 proceeds to step S204, andrequests a link to the communication unit 29.

In other words, when an ID packet is transmitted from the communicationunit 89 to the communication unit 29, and an ID packet identical to theabove ID packet is sent back from the communication unit 29 to thecommunication unit 89, an FHS packet which includes the Bluetoothaddress and Bluetooth clock of the communication unit 89 is transmittedfrom the communication unit 89 to the communication unit 29.

When, in step S224, the FHS packet transmitted from the communicationunit 89 is received by the communication unit 29, synchronization infrequency domain (frequency hopping pattern) and time domain (time slot)is established between the communication unit 89 and the communicationunit 29, thus establishing a data link (communication link) (State 1)

For example, when a data link in accordance with Bluetooth isestablished between the communication unit 29 and the communication unit89 for the first time, in step S205, the communication unit 89 transmitsa PIN (Personal Identification Number) code to the communication unit29, and mutual authentication is performed.

In step S225, the PIN code transmitted from the communication unit 89 isreceived by the communication unit 29. After that, various link keysbased on the PIN code and random numbers are set between thecommunication unit 89 and the communication unit 29.

The transmission and reception of the PIN code may be performed afterthe PIN code is encrypted by using a public key provided from thecommunication unit 29 to the communication unit 89. In other words, inthis case, the communication unit 29 manages a secret key correspondingto the public key provided to the communication unit 89 by itself. Thiscan enhance security, and it is more ensured that communication inaccordance with Bluetooth can be executed only between the personalcomputer 1 and the PDA 1.

In step S206, the communication unit 89 transmits the device ID set inthe PDA 11 to the communication unit 29.

In step S226, the device ID transmitted from the communication unit 89is received by the communication unit 29, and, in step S227, isregistered on the connection permission list managed by the personalcomputer 1.

The device ID registered in the personal computer 1 is used forauthentication which is performed when communication in accordance withthe normal power mode is initiated.

Because the communication link established as described above iseffective in the range of several centimeters which is reached by theradio waves from the communication unit 89 in which the very weak powermode is set, in step S206, the communication unit 89 requests thecommunication unit 29 to temporarily break the data link so thatcommunication with the communication unit 29 is possible, even if thereis some distance therebetween. At this time, the information acquired inthe steps, such as the Bluetooth address of the communication unit 29and the PIN code, is stored in the communication unit 89.

When receiving the request in step S228, similarly to the communicationunit 89, the communication unit 29 stores information which has beenacquired, such as the Bluetooth address of the communication unit 89 andthe PIN code, and breaks the data link (State 2).

When the PDA 11 is instructed to connect to the personal computer 1again, the communication unit 89 sets, based on control by the CPU 101,the mode of output power to the normal power mode. This causes Bluetoothradio waves from the communication unit 89 to reach, for example, arange of several tens of centimeters.

Proceeding to step S209, based on the information stored just before thedata link is broken, the communication unit 89 specifies the personalcomputer 1 as the other terminal in communication, and transmits thedevice ID and requests a connection to the communication unit 29.

When this request is received by the communication unit 29 in step S229,the CPU 21 proceeds to step S230, and determines whether or not thedevice ID transmitted by the communication unit 89 (the PDA 11) isregistered on the connection permission list. When determining that thedevice ID is registered, the CPU 21 permits the PDA 11 to connect.

In other words, based on the information which is transmitted andreceived in communication in accordance with the very weak power mode,and is stored, both terminals are set, thus activating a state having adata link established between the communication unit 89 and thecommunication unit 29, that is, a state in which communication inaccordance with Bluetooth can be performed, for example, in a range ofseveral tens of centimeters which is reached by the radio waves from thecommunication unit 89, in which the normal power mode is set. (State 3)

As described above, even if the personal computer 1 and the PDA 11 arenot provided with a reader and an IC tag, the user can register a setdevice ID of the PDA 11 in the personal computer 1 by simply bringingthe PDA 11 close to the personal computer 1, and initiates communicationin accordance with the normal power mode with the personal computer 1.

Although in the foregoing a device ID is transmitted from the PDA 11 tothe personal computer 1 when communication in accordance with the veryweak power mode is established, as FIG. 16 shows, information, such asan address and a password, is transmitted from the personal computer 1to the PDA 11, and access is controlled based on the transmittedinformation.

Next, processing in which, when communication in accordance with thevery weak power mode is established, not only the information such asthe above device ID, but also an exterior image indicating a device tobe connected is transmitted and received and the image is displayed, isdescribed with reference to the flowchart in FIG. 26.

In this example, when the communication in accordance with the very weakpower mode is established, an exterior image of the personal computer 1which is prepared beforehand can be transmitted from the personalcomputer 1 to the PDA 11.

Processing in steps S241 to S246 by the PDA 11, and processing in stepsS261 to S267 by the personal computer 1 are similar to that in stepsS201 to S206 in FIG. 25 and that in steps S221 to S227, respectively.

Specifically, the very weak power mode is used to establish a data linkcommunicatable within a range of, for example, several centimeters, andthe device ID transmitted from the communication unit 89 in the PDA 11is received by the communication unit 29 in the personal computer 1.

When receiving the PIN code, in step S268, the communication unit 29transmits, to the communication unit 89, the exterior image of thepersonal computer 1 which is prepared beforehand.

In step S247, the exterior image transmitted from the communication unit29 is received by the communication unit 89, and is stored in thestorage unit 88, or the like, of the PDA 11.

In step S248, the communication unit 89 requests the communication unit29 to break the data link in accordance with the very weak power mode,and temporarily breaks the data link.

After that, when the PDA 11 is instructed to connect to the personalcomputer 1 by the user, the communication unit 89 proceeds to step S249,and sets the normal power mode based on control by the CPU 81.

In step S250, based on the stored image data, the CPU 81 controls thedisplay unit 86 to display the exterior image of the personal computer1. This enables the user to confirm beforehand a terminal as the otherside in communication to which the data link in accordance with thenormal power mode is established.

For example, in step S251, when the PDA 11 is instructed by the user toconnect to the personal computer whose exterior image is displayed onthe display unit 86, the communication unit 89 proceeds to step S252,and transmits the device ID and requests a link to the communicationunit 29 in accordance with the normal power mode.

When the request is received by the communication unit 29 in step S270,and device ID authentication is completed, the data link in accordancewith the normal power mode is established (State 3).

As described above, based on the data transmitted when the data link inaccordance with the very weak power mode is established, the exteriorimage of the terminal is displayed whereby it is more ensured thatcommunication with the terminal as the other side in communication whichis desired by the user can be established.

Although in the foregoing an exterior image is transmitted asinformation representing a device as the other side in communicationwhen communication in accordance with the very weak power mode isestablished, not only the image; but also various types ofcharacteristic information, such as the name of the device as the otherside in communication, may be displayed for the user.

In addition, audio information concerning the device as the other sidein communication is transmitted, and audio guidance based thereon isoutput, whereby, even if a device which receives the audio informationincludes no display unit, information concerning the device to beconnected can be presented for the user beforehand.

Although the above consecutive processing can be executed by hardware,it can be executed by software.

In the case of using software to execute the consecutive processing,programs constituting the software are installed from a network orrecording media into, for example, a computer built into dedicatedhardware, or a general-purpose personal computer in which, by installingvarious programs, various functions can be executed.

As FIG. 2 shows, the recording media include, not only package mediaconstituted by a magnetic disk 31 (including a floppy disk), an opticaldisk 32 (CD-ROM (Compact Disk-Read Only Memory) and a DVD (DigitalVersatile Disk), a magneto-optical disk 33 (including MD (registeredtrademark (Mini Disk)), etc., which are distributed separately from thedevice body in order to provide programs to users, but also the ROM 22,in which a program is recorded, and a hard disk included in the storageunit 28, which are provided to users in a state incorporated beforehandin the device body.

In this Specification, the steps that describe programs recorded on therecording media obviously include time-series processes performed indescribed order, and also include processes executed in parallel orseparately.

Also, in this Specification, the system means the entirety of an deviceconstituted by a plurality of devices.

INDUSTRIAL APPLICABILITY

According to the present invention, simple and secure restricted accesscan be performed.

The invention claimed is:
 1. An information processing apparatuscomprising: a storing unit for storing a first number; an acquiring unitfor acquiring a second number from another information processingapparatus by short distance wireless communication; a comparing unit forcomparing the first number with the second number; and an establishingunit for establishing wireless communication with the other informationprocessing apparatus, wherein the establishing unit establishes wirelesscommunication by a request determined based on a result of thecomparison.
 2. The information processing apparatus of claim 1, furthercomprising: a communication unit for receiving an instruction tocommunicate with the other information processing apparatus.
 3. Theinformation processing apparatus of claim 2, wherein the acquiring unitacquires the second number in response to the instruction.
 4. Theinformation processing apparatus of claim 2, wherein the instructionincludes the request to establish a connection with the otherinformation processing apparatus.
 5. The information processingapparatus of claim 2, wherein the instruction includes the secondnumber.
 6. The information processing apparatus of claim 2, wherein theestablishing unit establishes the wireless communication with the otherinformation processing apparatus after receiving the instruction.
 7. Theinformation processing apparatus of claim 2, wherein the informationprocessing apparatus is in a first mode before acquiring the secondnumber from another information processing apparatus.
 8. The informationprocessing apparatus of claim 7, wherein the information processingapparatus switches from the first mode to a second mode to establish thewireless communication with the other information processing apparatus.9. The information processing apparatus of claim 1, wherein the firstand second numbers include random numbers.
 10. The informationprocessing apparatus of claim 1, wherein comparing the first number withthe second number includes performing a comparison between randomnumbers.
 11. The information processing apparatus of claim 10, furthercomprising: a display for displaying content received from the otherinformation processing apparatus by the wireless communication.
 12. Theinformation processing apparatus of claim 1, wherein the wirelesscommunication is Bluetooth or wireless LAN.
 13. The informationprocessing apparatus of claim 1, further comprising: an authenticationunit for authenticating the other information processing apparatus. 14.The information processing apparatus of claim 13, wherein theauthentication unit performs mutual authentication between theinformation processing apparatus and the other information processingapparatus.
 15. The information processing apparatus of claim 13, whereinthe authentication unit performs mutual authentication between theinformation processing apparatus and the other information processingapparatus before establishing the wireless communication with the otherinformation processing apparatus.
 16. The information processingapparatus of claim 13, wherein the authentication unit authenticates theother information processing apparatus before establishing the wirelesscommunication with the other information processing apparatus.
 17. Acommunication method being executed by an information processingapparatus, comprising: storing, in a storage unit of the informationprocessing apparatus, a first number; acquiring a second number fromanother information processing apparatus by short distance wirelesscommunication; comparing the first number with the second number; andestablishing wireless communication with the other informationprocessing apparatus, wherein the wireless communication is establishedby a request determined based on a result of the comparison.
 18. Themethod of claim 17, further comprising: switching, the informationprocessing apparatus, from a first mode to a second mode to establishthe wireless communication with the other information processingapparatus.
 19. The method of claim 17, further comprising:authenticating the other information processing apparatus beforeestablishing the wireless communication with the other informationprocessing apparatus.
 20. The method of claim 17, further comprising:receiving an instruction to communicate with the other informationprocessing apparatus, wherein the instruction includes the request toestablish a connection the other information processing apparatus, andthe second number is acquired in response to the instruction.
 21. Themethod of claim 17, wherein the first and second numbers include randomnumbers.
 22. The method of claim 17, wherein comparing the first andsecond numbers includes performing a comparison between random numbers.23. The method of claim 17, wherein the wireless communication isBluetooth or wireless LAN.
 24. A computer-readable storage mediumcomprising instructions which, when executed on a processor, cause theprocessor to perform a communication method between an informationprocessing apparatus and another information processing apparatus, themethod comprising: storing a first number; acquiring a second numberfrom another information processing apparatus by short distance wirelesscommunication; comparing the first number with the second number; andestablishing wireless communication with the other informationprocessing apparatus, wherein the wireless communication is establishedby a request determined based on a result of the comparison.
 25. Thecomputer-readable storage medium of claim 24, wherein the method furthercomprises: authenticating the other information processing apparatusbefore establishing the wireless communication with the otherinformation processing apparatus; and switching, the informationprocessing apparatus, from a first mode to a second mode to establishthe wireless communication with the other information processingapparatus.
 26. The computer-readable storage medium of claim 24, whereinthe first and second numbers include random numbers.
 27. Thecomputer-readable storage medium of claim 24, wherein the wirelesscommunication is Bluetooth or wireless LAN.
 28. An informationprocessing apparatus comprising: a storing unit for storing a firstnumber; an acquiring unit for acquiring a second number from anotherinformation processing apparatus by short distance wirelesscommunication; a comparing unit for comparing the first number with thesecond number; a determining unit for determining, based on a result ofthe comparison, whether to use a first request corresponding to theinformation processing apparatus or a second request corresponding tothe other information processing apparatus; and an establishing unit forestablishing wireless communication with the other informationprocessing apparatus based one of the first request or the secondrequest determined by the determining unit.
 29. The informationprocessing apparatus of claim 28, wherein the first number includes arandom number.
 30. The information processing apparatus of claim 28,wherein the second number includes a random number.
 31. The informationprocessing apparatus of claim 28, wherein comparing the first numberwith the second number includes performing a comparison between randomnumbers.
 32. The information processing apparatus of claim 28, whereinthe wireless communication is Bluetooth or wireless LAN.
 33. Acommunication method being executed by an information processingapparatus, comprising: storing, in a storage unit of the informationprocessing apparatus, a first number; acquiring a second number fromanother information processing apparatus by short distance wirelesscommunication; comparing the first number with the second number;determining, based on a result of the comparison, whether to use a firstrequest corresponding to the information processing apparatus or asecond request corresponding to the other information processingapparatus; and establishing wireless communication with the otherinformation processing apparatus based one of the first request or thesecond request determined by the determining unit.
 34. The communicationmethod of claim 33, wherein at least one of the first number and secondnumber include a random number.
 35. The communication method of claim33, wherein comparing the first number with the second number includesperforming a comparison between random numbers.
 36. A computer-readablestorage medium comprising instructions which, when executed on aprocessor, cause the processor to perform a communication method betweenan information processing apparatus and another information processingapparatus, the method comprising: storing a first number; acquiring asecond number from another information processing apparatus by shortdistance wireless communication; comparing the first number with thesecond number; determining, based on a result of the comparison, whetherto use a first request corresponding to the information processingapparatus or a second request corresponding to the other informationprocessing apparatus; and establishing wireless communication with theother information processing apparatus based one of the first request orthe second request determined by the determining unit.
 37. Thecomputer-readable storage medium of claim 36, wherein at least one ofthe first number and second number include a random number.
 38. Thecomputer-readable storage medium of claim 36, wherein comparing thefirst number with the second number includes performing a comparisonbetween random numbers.
 39. An information processing apparatuscomprising: a storing unit for storing a first number; a short distancecommunication unit configured to receive a second number from anotherinformation processing apparatus by short distance wirelesscommunication; a comparing unit configured to compare a first numberstored in the information processing apparatus with the second number;and a determining unit configured to determine, based on a result of thecomparison, whether to establish wireless communication with the otherinformation processing apparatus.
 40. The information processingapparatus of claim 39, wherein the first number comprises a randomnumber.
 41. The information processing apparatus of claim 39, whereinthe second number comprises a random number.
 42. The informationprocessing apparatus of claim 39, wherein the comparing performs acomparison of random numbers.
 43. The information processing apparatusof claim 39, wherein the information processing apparatus is configuredto transmit the message to the other information processing apparatus ifthe result of the comparison indicates that the first number is greaterthan the second number.
 44. The information processing apparatus ofclaim 43, wherein the first number comprises a random number.
 45. Theinformation processing apparatus of claim 43, wherein the second numbercomprises a random number.
 46. The information processing apparatus ofclaim 43, wherein the comparing performs a comparison of random numbers.47. The information processing apparatus of claim 46, wherein thewireless communication is Bluetooth or wireless LAN.
 48. The informationprocessing apparatus of claim 43, wherein the wireless communication isBluetooth or wireless LAN.
 49. The information processing apparatus ofclaim 39, wherein the wireless communication is Bluetooth or wirelessLAN.
 50. A communication method being executed by an informationprocessing apparatus, comprising: storing a first number in a storageunit of the information processing apparatus; receiving a second numberfrom another information processing apparatus by short distance wirelesscommunication; comparing the first number stored in the informationprocessing apparatus with the second number received from anotherinformation processing apparatus; and determining, based on a result ofthe comparison, whether to establish wireless communication with theother information processing apparatus.
 51. A computer-readable storagemedium comprising instructions which, when executed on a processor,cause the processor to perform a communication method between aninformation processing apparatus and another information processingapparatus, the method comprising: storing a first number in a storageunit of the information processing apparatus; receiving a second numberfrom another information processing apparatus by short distance wirelesscommunication; comparing the first number stored in the informationprocessing apparatus with the second number received from anotherinformation processing apparatus; and determining, based on a result ofthe comparison, whether to establish wireless communication with theother information processing apparatus.